U.S. patent application number 11/214944 was filed with the patent office on 2006-03-02 for film pattern producing method, and producing method for electronic device, electron-emitting device and electron source substrate utilizing the same.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Tsuyoshi Furuse, Kazuhiro Kagami, Takeru Mizue, Shosei Mori, Masahiro Terada.
Application Number | 20060046208 11/214944 |
Document ID | / |
Family ID | 35943701 |
Filed Date | 2006-03-02 |
United States Patent
Application |
20060046208 |
Kind Code |
A1 |
Mori; Shosei ; et
al. |
March 2, 2006 |
Film pattern producing method, and producing method for electronic
device, electron-emitting device and electron source substrate
utilizing the same
Abstract
A method for producing a film pattern comprises a step of
forming a resin film on a substrate surface; a step of
incorporating into the resin film a constituent of a conductive
film or a semiconductor film; a step of irradiating the resin film
with an ultraviolet light; and a step of heating the resin film at
a temperature not lower than a decomposition temperature of the
resin to form a conductive film or a semiconductor film on the
substrate, whereby the resin does not easily generate decomposition
residues to improve precision and quality of the produced film
pattern.
Inventors: |
Mori; Shosei;
(Hiratsuka-shi, JP) ; Furuse; Tsuyoshi;
(Isehara-shi, JP) ; Terada; Masahiro; (Hadano-shi,
JP) ; Mizue; Takeru; (Atsugi-shi, JP) ;
Kagami; Kazuhiro; (Atsugi-shi, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CANON KABUSHIKI KAISHA
TOKYO
JP
|
Family ID: |
35943701 |
Appl. No.: |
11/214944 |
Filed: |
August 31, 2005 |
Current U.S.
Class: |
430/330 ;
430/324 |
Current CPC
Class: |
H05K 2203/1105 20130101;
G03F 7/405 20130101; H05K 2203/121 20130101; H05K 3/105 20130101;
H01J 9/027 20130101; G03F 7/0047 20130101; H01J 2201/3165
20130101 |
Class at
Publication: |
430/330 ;
430/324 |
International
Class: |
G03F 7/00 20060101
G03F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 1, 2004 |
JP |
2004-253985(PAT.) |
Claims
1. A method for producing a film pattern comprising: a step of
forming a resin film on a substrate surface; a step of
incorporating into the resin film a constituent of a conductive
film or a semiconductor film; a step of irradiating the resin film
with an ultraviolet light; and a step of heating the resin film at
a temperature not lower than a decomposition temperature of the
resin to form a conductive film or a semiconductor film on the
substrate.
2. A film pattern producing method according to claim 1, wherein
the ultraviolet irradiation is executed under a heating of the
resin film containing the constituent of the conductive film or the
semiconductor film.
3. A film pattern producing method according to claim 1, wherein
the ultraviolet irradiation is executed in the presence of
ozone.
4. A film pattern producing method according to claim 1, wherein
the resin film is formed of a resin containing an ion exchange
group.
5. A film pattern producing method according to claim 1, wherein
the constituent of the conductive film or the semiconductor film is
either one selected from gold, silver, copper, ruthenium,
palladium, rhodium, bismuth, vanadium, chromium, tin, lead,
silicon, zinc, indium and nickel.
6. A film pattern producing method according to claim 1, wherein
the liquid containing the constituent of the conductive film or the
semiconductor film is a liquid containing a metal complex.
7. A film pattern producing method according to claim 1, wherein
the liquid containing the constituent of the conductive film or the
semiconductor film is an aqueous liquid.
8. A method for producing an electronic device including a
substrate provided with a circuit having a conductive or
semiconductor film pattern in at least a part thereof, wherein at
least a part of the film pattern is formed by a film pattern
producing method according to claim 1.
9. A method for producing an electron-emitting device including a
conductive film pattern as a constituent component thereof, wherein
the film pattern is formed by a film pattern producing method
according to claim 1.
10. A method for producing an electron source substrate including
plural electron-emitting devices formed on a substrate and wirings
for driving the electron-emitting devices in which at least a part
of the electron-emitting devices and the wirings is formed by a
conductive film pattern, wherein at least a part of the film
pattern is formed by a film pattern producing method according to
claim 1.
11. A method for producing an image forming apparatus, which
comprises positioning an electron source substrate obtain by a
producing method according to claim 10 in an opposed relationship
to a substrate having an image forming member capable of forming an
image by an electron beam irradiation.
12. A method of producing a film pattern comprising: a step of
forming a resin film on a substrate; a step of incorporating into
the resin film a liquid containing a constituent of a conductive
film or a semiconductor film; and a step of baking the resin film
to form a conductive film or a semiconductor film, wherein, step of
incorporating into the resin film the liquid containing the
constituent of a conductive film or the semiconductor film, the
resin film containing the constituent of the conductive film or the
semiconductor film is irradiated with an ultraviolet light before
the resin film is heated to a decomposition temperature of the
resin.
13. A film pattern producing method according to claim 12, wherein
the ultraviolet irradiation is executed in the presence of
ozone.
14. A film pattern producing method according to claim 12, wherein
the resin film is formed of a resin having an ion exchange
group.
15. A film pattern producing method according to claim 12, wherein
the constituent of the conductive film or the semiconductor film is
either one selected from gold, silver, copper, ruthenium,
palladium, rhodium, bismuth, vanadium, chromium, tin, lead,
silicon, zinc, indium and nickel.
16. A film pattern producing method according to claim 12, wherein
the liquid containing the constituent of the conductive film or the
semiconductor film is a liquid containing a metal complex.
17. A film pattern producing method according to claim 12, wherein
the liquid containing the constituent of the conductive film or the
semiconductor film is an aqueous liquid.
18. A method for producing an electronic device including a
substrate provided with a circuit having a conductive or
semiconductor film pattern in at least a part thereof, wherein at
least a part of the film pattern is formed by a film pattern
producing method according to claim 12.
19. A method for producing an electron-emitting device including a
conductive film pattern as a constituent component thereof, wherein
the film pattern is formed by a film pattern producing method
according to claim 12.
20. A method for producing an electron source substrate including
plural electron-emitting devices formed on a substrate and wirings
for driving the electron-emitting devices in which at least a part
of the electron-emitting devices and the wirings is formed by a
conductive film pattern, wherein at least a part of the film
pattern is formed by a film pattern producing method according to
claim 12.
21. A method for producing an image forming apparatus, which
comprises positioning an electron source substrate obtain by a
producing method according to claim 20 in an opposed relationship
to a substrate having an image forming member capable of forming an
image by an electron beam irradiation.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method for producing a
film pattern that can be utilized for forming an electrode, a
wiring or a component for an electron-emitting device, formed as a
patterned conductive film, or for forming a patterned semiconductor
film in a thin film transistor, and a producing method for an
electronic device, an electron-emitting device, an electron source
substrate and an image forming apparatus, utilizing the same.
[0003] 2. Related Background Art
[0004] It is already known to obtain a conductive film pattern on a
substrate by forming a resin pattern with a photosensitive resin on
the substrate, causing the resin pattern to absorb a solution
containing a metal component and baking such resin pattern, and to
produce an electron-emitting device, an electron source substrate
or an image forming apparatus, by utilizing such film pattern
formation (for example cf. Japanese Patent Application Laid-open
No. 2003-36781).
[0005] However, a film pattern formation by such prior method tends
to result in a fluctuation in the pattern, and is not sufficient in
a pattern precision for use in a wiring or an electrode of a high
definition image forming apparatus.
SUMMARY OF THE INVENTION
[0006] An object of the present invention is to suppress a
fluctuation in the obtained film pattern thereby enabling to obtain
a highly precise pattern.
[0007] The present invention provides a method for producing a film
pattern comprises a step of forming a resin film on a substrate
surface; a step of incorporating into the resin film a constituent
of a conductive film or a semiconductor film; a step of irradiating
the resin film with an ultraviolet light; and a step of heating the
resin film at a temperature not lower than a decomposition
temperature of the resin to form a conductive film or a
semiconductor film on the substrate, whereby the resin does not
easily generate decomposition residues to improve precision and
quality of the produced film pattern.
[0008] The present invention also provides a method of producing a
film pattern comprising: a step of forming a resin film on a
substrate; a step of incorporating into the resin film a liquid
containing a constituent of a conductive film or a semiconductor
film; and a step of baking the resin film to form a conductive film
or a semiconductor film, wherein, step of incorporating into the
resin film the liquid containing the constituent of a conductive
film or the semiconductor film, the resin film containing the
constituent of the conductive film or the semiconductor film is
irradiated with an ultraviolet light before the resin film is
heated to a decomposition temperature of the resin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIGS. 1A and 1B are respectively a cross-sectional view and
a plan view, showing a configuration of an electron-emitting device
that can be produced with a film pattern forming method of the
invention; and
[0010] FIG. 2 is a partially cut-off perspective view schematically
showing an image forming apparatus utilizing an electron source
substrate that can be produced by the film pattern forming method
of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] The present invention has been made by a finding that a
fluctuation in the obtained film pattern has been caused by a
decomposition residue of the resin constituting the resin
pattern.
[0012] Therefore, the present invention provides a method for
producing a film pattern comprising: a step of forming a resin film
on a substrate surface;
[0013] a step of incorporating into the resin film a constituent of
a conductive film or a semiconductor film; a step of irradiating
the resin film with an ultraviolet light; and a step of heating the
resin film at a temperature not lower than a decomposition
temperature of the resin to form a conductive film or a
semiconductor film on the substrate.
[0014] The present invention also provides a method of producing a
film pattern comprising: a step of forming a resin film on a
substrate; a step of incorporating into the resin film a liquid
containing a constituent of a conductive film or a semiconductor
film; and a step of baking the resin film to form a conductive film
or a semiconductor film, wherein, step of incorporating into the
resin film the liquid containing the constituent of a conductive
film or the semiconductor film, the resin film containing the
constituent of the conductive film or the semiconductor film is
irradiated with an ultraviolet light before the resin film is
heated to a decomposition temperature of the resin.
[0015] Further, the present invention provides a producing method
for an electronic device, an electron-emitting device, an electron
source substrate and an image forming apparatus, utilizing the
aforementioned film pattern producing method.
[0016] According to the invention, the constituent resin of the
resin pattern is rendered easily thermally decomposable by the
ultraviolet irradiation, prior to the thermal decomposition in the
baking step, and does not easily generate decomposition residue,
thereby improving a precision of the obtained film pattern.
[0017] In the invention, the irradiation of the resin film with the
ultraviolet light is executed after the step of impregnating the
resin film with the constituent of the conductive film or the
semiconductor film, and before the resin film is heated to the
decomposition temperature of the constituent resin thereof.
Therefore, the ultraviolet irradiation may be executed, after the
step of impregnating the resin film with the constituent of the
conductive film or the semiconductor film, either prior to the
heating of the resin film in the baking step or after the start of
the heating in the baking step but before the resin film is heated
to the decomposition temperature of the constituent resin. Such
ultraviolet irradiation allows to form a fine film pattern
uniformly and little fluctuation, and, for example in the
preparation of a display apparatus, to achieve a high definition.
Also such method, being simple, can be executed in an inexpensive
apparatus and can also suppress an amount of use of the film
pattern forming material.
[0018] A liquid to be employed in the embodiment of the invention
contains a component constituting the conductive film or the
semiconductor film, and may be, as long as capable of forming a
conductive film or a semiconductor film by a baking, an organic
solvent solution based on an organic solvent type solvent
containing an organic solvent by 50 wt.% or more, or an aqueous
solution based on an aqueous solvent containing water by 50 wt. %
or more. In the present invention, a metal means to include an
alloy.
[0019] The present invention can form a conductive or semiconductor
film pattern, which can be utilized for forming an electrode, a
wiring, a device film of a surface conduction electron-emitting
device, or a patterned semiconductor film in a thin film
transistor. More specifically, the present invention is applicable
to the production of an electronic device, an electron-emitting
device, an electron source substrate or an image forming
apparatus.
[0020] An electronic device means an apparatus equipped with a
substrate provided with a circuit including a conductive or
semiconductor film pattern in at least a part thereof, and
includes, for example, a liquid crystal display panel and a
computer.
[0021] The present invention is further applicable to the
production of an electron-emitting device, an electron source
substrate provided with a plurality of such electron-emitting
devices, and an image forming apparatus employing the electron
source substrate.
[0022] An example of the electron-emitting device is a surface
conduction electron-emitting device, which is constructed by
forming a conductive film in connection with a pair of device
electrodes formed in mutually opposed positions on an electrically
insulating substrate, and then applying an energization process,
called a forming process, to the conductive film to locally
destruct, deform or denature the conductive film thereby forming a
portion of a high electrical resistance including a fissure, and
which shows a phenomenon of an electron emission from the portion
of electrical high resistance including the fissure (electron
emitting portion) when a current is supplied along the conductive
film. The present invention is applicable not only to the
aforementioned surface conduction electron-emitting device, but
also to other electron-emitting devices having a conductive film
pattern as a constituent. Such other electron-emitting devices
include an electron-emitting device of a field emission (FE) type,
and an electron-emitting device having a metal/insulator/metal
(MIM) configuration.
[0023] An electron source substrate is a substrate provided with a
plurality of electron-emitting devices and a wiring for driving the
electron-emitting devices, and, in case at least a part of the
electron-emitting devices and the wiring is constituted of a film
pattern, such electron source substrate can be produced by forming
at least a part of such film pattern by the film pattern forming
method of the present invention.
[0024] An electron source substrate, utilizing the aforementioned
surface conduction electron-emitting device, includes a
ladder-shape configuration in which plural electron-emitting
devices, each having a pair of device electrodes, are arranged
along an X-direction and a Y-direction of a matrix pattern, and one
of the device electrodes and the other thereof in each of the
plural electron-emitting devices in a same row are respectively
connected to common wirings. In the electron source substrate of
such ladder-shaped configuration, it is possible, by providing a
control electrode (also called a grid) above each electron-emitting
device, to control, among the electron-emitting devices driven for
each row, the device from which the electrons are to be
emitted.
[0025] Also there is known an electron source substrate of
so-called single matrix arrangement, in which plural
electron-emitting devices are arranged along an X-direction and a
Y-direction of a matrix pattern, and one of the device electrodes
in each of the plural electron-emitting devices in a same row is
commonly connected to a wiring in the X-direction, while the other
device electrode in each of the plural electron-emitting devices in
a same column is connected commonly to a wiring in the
Y-direction.
[0026] Also an image forming apparatus is known to be formed by
combining, in a mutually opposed relationship, such electron source
and an image forming member which forms an image by the irradiation
of an electron beam emitted from the electron-emitting device of
the electron source. A display panel usable as a television or a
computer display can be obtained by utilizing, as the image forming
member, a member having a phosphor which emits a visible light by
the electrons. Also there can be obtained a copying machine or a
printer by employing a photosensitive drum as the image forming
member and by developing a latent image, formed on the
photosensitive drum by the irradiation with the electron beam, with
a toner.
[0027] The present invention will be further clarified in the
following.
[0028] (1) Resin Film Forming Material
[0029] A resin film forming material to be employed in the present
invention can be a photosensitive resin. The photosensitive resin
to be employed is not particularly restricted as long as a resin
film formed with such resin can absorb a liquid containing a
component for constituting the conductive film or the semiconductor
film as will be explained later, and may be a water-soluble
photosensitive resin or a solvent-soluble photosensitive resin. A
water-soluble photosensitive resin means a photosensitive resin
which can be developed, in a development step to be explained
later, with water or a developer containing water by 50 wt. % or
more, and a solvent-soluble photosensitive resin means a
photosensitive resin which can be developed, in the development
step, with an organic solvent or a developer containing an organic
solvent by 50 wt. % or more.
[0030] The photosensitive resin may be of a type containing a
photosensitive group in a resin structure, or a type in which a
sensitizer is mixed with a resin, such as a cyclized
rubber-bisazide resist. In the photosensitive resin of either type,
a photoreaction initiator or a photoreaction inhibitor may be
suitably mixed. Also there may be employed a type in which a
photosensitive resin film soluble in a developer solution becomes
insoluble therein by a light irradiation (negative type) or a type
in which a photosensitive resin film insoluble in a developer
solution becomes soluble therein by a light irradiation (positive
type).
[0031] In the present invention, general photosensitive resins may
be employed widely as explained above, but there is preferred a
resin capable of an ion exchange by reacting a film forming
component in a solution to be explained later, in order to improve
the absorption of a component constituting the conductive film or
the semiconductor film, thereby improving the efficiency of
utilization of materials, and for forming a pattern of a better
shape. A resin capable of ion exchange is a resin having an ion
exchanging group, and is particularly preferably a resin having a
carboxylic acid group because of the ease for forming a pattern of
a better shape. Also a water-soluble photosensitive resin is
preferable in consideration of ease of maintaining a satisfactory
work environment and a smaller burden of the waste material on the
environment.
[0032] Further for such water-soluble photosensitive resin, there
can be employed a developer solution containing water by 50 wt. %
or more and containing a lower alcohol such as methyl alcohol or
ethyl alcohol, for increasing the drying speed, within a range less
than 50 wt. %, or a developer solution containing a component for
promoting dissolution or improving stability of the photosensitive
resin component. However, from the standpoint of alleviating an
environmental burden, there is preferred a resin developable with a
developer solution of a water content of 70 wt. % or higher, more
preferably a resin developable with a developer solution of a water
content of 90 wt. % or higher, and most preferably a resin
developable with water only as the developer. Such water-soluble
photosensitive resin can be, for example, formed by a water-soluble
resin such as a polyvinyl alcohol resin or a polyvinylpyrrolidone
resin.
[0033] (2) Liquid Containing Component Constituting Conductive Film
or Semiconductor Film
[0034] A liquid containing a component constituting the conductive
film or the semiconductor film, to be employed in the present
invention, may be any liquid capable of forming a conductive film
or a semiconductor film by drying and baking, and a component for
constituting the conductive film or the semiconductor film can be a
metal or a metal compound. In consideration of an application to
the manufacture of an electronic device, an electron-emitting
device, an electron source substrate or an image display apparatus,
the component for constituting the conductive film or the
semiconductor film is preferably one selected from gold, silver,
copper, ruthenium, palladium, rhodium, bismuth, vanadium, chromium,
tin, lead, silicon, zinc, indium and nickel. Also the liquid
containing such constituent may be an organic solvent solution
utilizing a organic solvent type solvent containing an organic
solvent by 50 wt. % or more, or an aqueous solution utilizing an
aqueous solvent containing water by 50 wt. % or more. The liquid
containing the constituent can be easily obtained by dissolving a
metalorganic compound such as a metal complex soluble in water or
an organic solvent in an aqueous solvent or in an organic solvent
type solvent.
[0035] The liquid to be employed in the present invention is
preferably an aqueous liquid, in consideration of ease of
maintaining a satisfactory work environment and a smaller burden of
the waste material on the environment as in the aforementioned
photosensitive resin. An aqueous solvent for such aqueous liquid
may be a liquid containing water by 50 wt. % or more and containing
a lower alcohol such as methyl alcohol or ethyl alcohol, for
increasing the drying speed, within a range less than 50 wt. %, or
a liquid containing a component for promoting dissolution or
improving stability of the metalorganic compound. Particularly from
the standpoint of alleviating an environmental burden, there is
preferred a water content of 70 wt. % or higher, more preferably a
water content of 90 wt. % or higher, and most preferably water
only.
[0036] (3) Producing Method for Conductive Film Pattern
[0037] A film pattern of a conductive film and/or a semiconductor
film employing a photosensitive resin as the resin can be formed by
a resin film forming step (coating step, drying step, exposure step
and developing step), an absorption step of impregnating the resin
film with the constituent of the conductive film or the
semiconductor film, a rinsing step executed if necessary, a baking
step and a milling step executed if necessary.
[0038] A coating step is a step of coating the aforementioned
photosensitive resin on a substrate on which the film pattern is to
be formed. The coating can be executed by various printing methods
(such as screen printing, offset printing, or flexo printing), a
spinner method, a dipping method, a spraying method, a stamping
method, a roller method, a slit coater method or an ink jet
method.
[0039] A drying step is a step of evaporating a solvent in the
photosensitive resin film coated on the substrate in the coating
step, thereby drying the coated film. The drying of the coated film
may be executed at the room temperature, but is preferably executed
under heating, in order to reduce a drying time. Drying under
heating can be executed, for example, with an oven without air
blowing, a dryer, or a hot plate. Though dependent on a formulation
and a coating amount of the composition for forming
electrode/wiring to be coated, the drying can be generally achieved
by placing for 1-30 minutes at a temperature of 50-120.degree.
C.
[0040] An exposure step is a step of exposing the photosensitive
resin film dried in the drying step, to a predetermined pattern,
namely a pattern of a film to be produced (such as a predetermined
shape of electrode or wiring). An area to be exposed by a light
irradiation in the exposure step is different, depending on whether
the photosensitive resin to be employed is a negative type or a
positive type. In case of a negative type which becomes insoluble
in the developer solution by the light irradiation, the exposure is
executed by irradiating an area to be left of the resin film with a
light, but, in case of a positive type which becomes soluble in the
developer solution by the light irradiation, the exposure is
executed by irradiating an area other than the area to be left of
the resin film with a light. A selection of the light irradiated
area and the light non-irradiated area can be made in a similar as
in a mask formation in the ordinary photoresist.
[0041] A developing step is a step of eliminating, in the
photosensitive resin film exposed in the exposure step, an area
other than the area to be left of the resin film. In case of a
negative photosensitive resin, a photosensitive resin film not
subjected to a light irradiation is soluble in the developer
solution while a photosensitive resin film subjected to a light
irradiation is insoluble in the developer solution, so that the
development can be executed by dissolving and removing, with the
developer solution, the photosensitive resin film of a light
non-irradiated area, not insolubilized in the developer solution.
In case of a positive photosensitive resin, a photosensitive resin
film not subjected to a light irradiation is insoluble in the
developer solution while a photosensitive resin film subjected to a
light irradiation is solubilized in the developer solution, so that
the development can be executed by dissolving and removing, with
the developer solution, the photosensitive resin film of a light
irradiated area, solubilized in the developer solution.
[0042] In case of employing a water-soluble photosensitive resin,
the developer solution can be water or similar to a developer
solution employed for ordinary photoresists. Also in case of a
resin soluble in an organic solvent, the developer solution can be
an organic solvent or similar to a developer solution employed for
photoresists of solvent type.
[0043] An absorption step for impregnating the resin film with a
constituent of the conductive film or the semiconductor film is a
step of causing the resin film formed in the foregoing steps, to
absorb a liquid containing a constituent of the aforementioned
conductive film or the semiconductor film. The absorption is
executed by contacting the formed resin film with a liquid
containing a constituent of the conductive film or the
semiconductor film. More specifically, it can be achieved by a
dipping method of immersing in the liquid containing the
aforementioned constituent, or a coating method of coating the
resin film with a liquid containing the constituent by a spray or a
spin coating. Prior to the contact with the liquid containing the
constituent, it is possible also, for example in case of employing
the aforementioned aqueous liquid, to swell the resin film with the
aqueous solvent.
[0044] A rinsing step is a step, after impregnating the resin film
with the liquid containing the constituent of the conductive film
or the semiconductor film, of rinsing and eliminating an excessive
liquid adhering to the resin film or an excessive liquid adhering
to a portion other than the resin film. The rinsing step can be
executed by employing a rinsing liquid similar to the solvent in
the liquid containing the constituent of the conductive film or the
semiconductor film, and by a method of immersing the substrate
bearing the resin film in such rinsing liquid or by a method of
spraying the rinsing liquid to the substrate bearing the resin
film.
[0045] An ultraviolet irradiation, constituting the essence of the
present invention, is executed after the impregnation of the
constituent of the conductive film or the semiconductor film in the
resin film. The ultraviolet irradiation may be executed before the
baking step, but is preferably executed in the baking step, before
a constituent resin of the resin film under baking reaches a
starting temperature of thermal decomposition.
[0046] An ultraviolet irradiation executed in the present invention
is to facilitate a thermal decomposition of the constituent resin
of the resin film, and is preferably executed, in order to achieve
an efficient cleavage of a carbon bond of the constituent resin,
with a wavelength of 172-254 nm, for about 1-30 minutes so as to
obtain an exposure amount of 10-5000 mJ. The ultraviolet
irradiation with a low-pressure mercury lamp can be executed in a
short time, in an ozone atmosphere so as to achieve a more
efficient cleavage of the carbon bond in the constituent resin.
Also an ultraviolet irradiation with an excimer UV lamp can be
executed in a shorter time under a nitrogen atmosphere.
[0047] As a light source for the ultraviolet light, there can be
employed a low-pressure mercury lamp or an excimer UV lamp. The
ultraviolet irradiation is executed at a shorter wavelength
(172-254 nm) in comparison with the exposing ultraviolet
irradiation (360-365 nm) in the exposure step and at a higher
energy (several ten to several thousand millijoules), and requires
an irradiation amount of several to several thousand times in
comparison with the exposure amount in the photoprocess.
[0048] A baking step is a step of baking the resin film, subjected
to the developing step and the absorption step and the rinsing step
if necessary (namely the photosensitive resin film in the light
irradiated area in the negative type or the photosensitive resin
film in the light non-irradiated area in the positive type), to
decompose and eliminate an organic component in the resin film,
thereby forming a film pattern by the constituent of the conductive
film or the semiconductor film contained in the resin film. The
baking can be executed in the air, in case of forming a conductive
film pattern with a precious metal, but may be executed in vacuum
or in an oxygen-free atmosphere (for example in an inert gas
atmosphere such as nitrogen) in case of forming a conductive film
pattern with an easily oxidizable metal such as copper or
palladium.
[0049] The baking, though dependent on the type of the organic
component contained in the resin film, is generally executed for a
period of several to several tens of minutes at a temperature of
400-600.degree. C. The baking can be executed for example a hot-air
circulating oven, a belt oven, a tact oven, a hot plate or an IR
oven. The baking allows to obtain, on the substrate, a conductive
film and/or a semiconductor film in a predetermined pattern.
Particularly in the invention, since the baking can be executed
after the constituent resin of the resin film is rendered easily
thermally decomposable by the ultraviolet irradiation, the
constituent resin does not easily generate residues at the baking,
whereby the film pattern can be formed with an improved
uniformity.
[0050] (5) Producing Method for Electron-Emitting Device
[0051] The film pattern forming method of the invention is
applicable, as described before, to a producing method of an
electron-emitting device, and, in the following, there will be
explained an application to a producing method for a surface
conduction electron-emitting device.
[0052] FIGS. 1A and 1B are respectively a cross-sectional view and
a plan view, schematically showing a configuration of an
electron-emitting device that can be produced by the film pattern
producing method of the invention, wherein shown are a substrate 1,
device electrodes 2a, 2b, a device film 3 and an electron emitting
part 4.
[0053] As illustrated, the electron-emitting device of the
invention includes a device film 3 bridging a pair of device
electrodes 2a, 2b formed on the substrate 1. The device electrodes
2a, 2b and the device film 3 are formed as conductive film
patterns, and, after the formation thereof, an energization process
called a forming is applied between the device electrodes 2a, 2b to
form an electron emitting part 4 in a part of the device film 3.
The electron-emitting device is usually subjected, after the
forming process, to an activation process of applying a voltage
between the device electrodes 2a, 2b in the presence of an organic
gas to deposit carbon in the electron emitting part 4 and a
vicinity thereof, thereby improving the electron emitting
efficiency.
[0054] As the device electrodes 2a, 2b and the device film 3 are
formed as conductive film patterns as described above, either or
both of these components can be formed by the film pattern forming
method of the invention.
[0055] (6) Producing Method for Electron Source and Image Forming
Apparatus
[0056] The film pattern forming method of the invention is also
applicable, as described before, to a producing method for an
electron source substrate or an image forming apparatus, and, in
the following, there will be explained a producing method for an
electron source substrate utilizing a surface conduction
electron-emitting device and for an image forming apparatus
utilizing the same.
[0057] FIG. 2 is a partially cut-off perspective view schematically
showing an image forming apparatus, utilizing an electron source
substrate that can be produced with the film pattern forming method
of the invention.
[0058] An electron source substrate 10 has a simple matrix
structure in which an electron-emitting device 15, having device
electrodes 12a, 12b and a device film 13 including an electron
emitting part 14 is provided, on a substrate 11, in plural units
along X and Y directions and connected to Y-direction wirings
(lower wirings) 16 and X-direction wirings (upper wirings) 17, and,
the device electrode 2b of each electron-emitting device 15 is
connected to the Y-direction wiring 16, while the device electrode
2a of each electron-emitting device 15 is connected to the
X-direction wiring 17. The electron-emitting device 15 is basically
similar to that shown in FIGS. 1A and 1B, and the substrate 11, the
device electrodes 12a, 12b, the device film 13 and the electron
emitting part 14 respectively correspond to the substrate 1, the
device electrodes 2a, 2b, the device film 3 and the electron
emitting part 4 in FIGS. 1A and 1B.
[0059] The electron source substrate is provided on a rear plate
18. Opposed to the electron source substrate provided on the rear
plate 18, there is provided a face plate 21 having a phosphor film
19 and a metal back 20 on an internal surface, and a space between
the rear plate 18 and the face plate 21 is sealed by a supporting
frame 22 surrounding the periphery of the two to maintain a vacuum
atmosphere therein.
[0060] This image forming apparatus constitutes an image display
panel, in which a voltage is applied between the device electrodes
12a, 12b of an electron-emitting device 15 selected by lead
terminals X1-Xn, Y1-Ym respectively connected to the X-direction
wirings 17 and the Y-direction wirings 16 and a high voltage of
10-15 kV is applied from a high voltage terminal 22 to the metal
back 20, thereby irradiating an electron beam emitted from the
selected electron-emitting device 15 to the corresponding phosphor
and thus displaying an image.
[0061] The electron source substrate 10 in the aforementioned image
forming apparatus can be produced by forming device electrodes 12a,
12b of plural pairs, a device film 13 connecting each pair of the
device electrodes 12a, 12b, Y-direction wirings 16 connected to the
device electrodes 12b and X-direction wirings 17 connected to the
device electrodes 12a, and energizing each pair of the device
electrodes 12a, 12b thereby forming an electron emitting part 14 in
each device film 13.
[0062] The device electrodes 12a, 12b, the device film 13, the
Y-direction wirings 16 and the X-direction wirings 17 can be formed
as conductive film patterns, and the electron source substrate 10
can be prepared by forming any or all of these components by the
film pattern forming method of the invention. Also an image forming
apparatus (image display panel) can be produced by positioning in
an opposed relationship to a phosphor film 19, constituting an
image forming member for forming an image by an electron beam
irradiation.
EXAMPLES
Example 1
[0063] A photosensitive resin (methacrylic acid-methyl
methacrylate-ethyl acrylate-n-butyl acrylate-azobisisobutyronitrile
copolymer) was coated on an entire surface of a glass substrate (75
mm.times.75 mm.times.thickness 2.8 mm) and was dried for 2 minutes
at 80.degree. C. on a hot plate.
[0064] Then, with a photomask of a linear pattern of a line width
shown in Table 1, a pattern-forming area of the photosensitive
resin film was exposed with an ultra high-pressure mercury lamp
(illumination intensity=1600 mW/cm.sup.2), utilizing a Canon MPA
3200 (mirror projection mask aligner) with a scanning speed of 13
mm/sec and developed to obtain a resin pattern.
[0065] The substrate bearing the resin pattern was immersed in
purified water for 30 seconds, and then immersed for 180 seconds in
a Ru complex solution (aqueous solution of
tris(2,2'-bipyridyl)ruthenium (II) chloride, ruthenium content 0.1
wt. %) to cause the solution to be absorbed in the resin
pattern.
[0066] Then the substrate was taken out, rinsed for 5 seconds under
running water to wash off the Ru complex solution present between
the resin patterns, then subjected to an elimination of liquid by
blowing air, and dried for 3 minutes on a hot plate of 80.degree.
C. Then, after an ultraviolet irradiation of 2000 mJ with a
low-pressure mercury lamp, a baking was conducted in a hot-air
circulating oven for 1 hour at 500.degree. C.
[0067] An obtained linear film pattern of ruthenium oxide was
subjected to a measurement of a line width by a line width
measuring instrument, and a linearity of the linear film pattern
was evaluated by a fluctuation from the mask pattern
(3.sigma./average, .sigma.=standard deviation of samples). The line
pattern had a width of 6, 8, 10, 20 or 50 .mu.m and a length of
1000 .mu.m, and, on each film pattern, the line width was measured
at 90 points at a pitch of 10 .mu.m.
[0068] Results are shown in Table 1.
Example 2
[0069] A substrate bearing a resin pattern, subjected to an
impregnation with a Ru complex solution, a rinsing and a drying,
was prepared in the same manner as in Example 1. The substrate was
charged in a belt oven, subjected to an ultraviolet irradiation of
2000 mJ with a low-pressure mercury lamp at 200.degree. C. and then
baked at 500.degree. C. in the belt oven.
[0070] An obtained ruthenium oxide film pattern was subjected to
measurements and evaluation as in Example 1.
[0071] Obtained results are shown in Table 1.
Comparative Example 1
[0072] A linear film pattern of ruthenium oxide was obtained in the
same manner as in Example 1 except that the ultraviolet irradiation
with the low-pressure mercury lamp was not executed, and was
subjected to measurements and evaluation as in Example 1.
[0073] Obtained results are shown in Table 1. TABLE-US-00001 TABLE
1 Mask line Fluctuation (%) width (.mu.m) Example 1 Example 2 Comp.
Ex. 1 6 0.6 0.5 2.0 8 0.5 0.4 1.5 10 0.4 0.5 1.3 20 0.5 0.4 1.1 50
0.5 0.5 1.2
[0074] Also an electron-emitting device, produced by forming the
device electrodes 2a, 2b shown in FIGS. 1A and 1B in the methods of
the foregoing Examples showed satisfactory electron emitting
characteristics with a high reproducibility.
[0075] Also in case of forming the device electrodes 12a, 12b of
the electron-emitting devices 15 in the electron source substrate
10 shown in FIG. 2, by the methods described in the foregoing
Examples, the electron emitting characteristics were uniform among
the electron-emitting devices.
[0076] Also in case of forming the device electrodes 12a, 12b of
the electron-emitting devices 15 and the Y-direction wirings (lower
wirings) 16 and the X-direction wirings (upper wirings) 17 in the
electron source substrate 10 shown in FIG. 2, by the methods
described in the foregoing Examples, the electron emitting
characteristics were more uniform among the electron-emitting
devices.
[0077] Also a high reliable image display apparatus with a
satisfactory display performance could be obtained by employing the
electron source substrate 10 produced in the aforementioned method
in the image display apparatus shown in FIG. 2.
[0078] In the foregoing examples, there have been shown cases of
executing a baking and an ultraviolet irradiation once each, but
the present invention is not limited to such example. For example,
there can also be selected a method of executing an ultraviolet
irradiation and a baking, and then further executing the
ultraviolet irradiation and the baking plural times, and such
method can be selected without departing the concept or spirit of
the present invention.
[0079] This application claims priority from Japanese Patent
Application No. 2004-253985 filed Sep. 1, 2004, which is hereby
incorporated by reference herein.
* * * * *